EcoCTD for profiling oceanic physical-biological properties from an underway ship

Author Posting. © American Meteorological Society, 2020. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of the Atmospheric and Oceanic Technology 37(5), (2020): 825-840, doi:10.1175/JTECH-D-19-0145.1.The study of ocean dynamics and biophysical variability at submesoscales of O(1) km and O(1) h raises several observational challenges. To address these by underway sampling, we recently developed a towed profiler called the EcoCTD, capable of concurrently measuring both hydrographic and bio-optical properties such as oxygen, chlorophyll fluorescence, and optical backscatter. The EcoCTD presents an attractive alternative to currently used towed platforms due to its light footprint, versatility in the field, and ease of deployment and recovery without cranes or heavy-duty winches. We demonstrate its use for gathering high-quality data at submesoscale spatiotemporal resolution. A dataset of bio-optical and hydrographic properties, collected with the EcoCTD during field trials in 2018, highlights its scientific potential for the study of physical–biological interactions at submesoscales.Authors would like to acknowledge Melissa Omand, Ben Pietro, and Jing He for their valuable input during the design phase of the EcoCTD, as well as for their support for deploying the EcoCTD in the field. We are grateful to Eva Alou, Andrea Carbonero, and John Allen for providing calibrated data from the shipboard CTD. Authors would also like to thank Don Peters along with Dynamics System Analysis Ltd. for facilitating access to ProteusDS and providing support in using the software. We are grateful to the crew of the RV Armstrong and NRV Alliance for their support in the field. Development of the EcoCTD is supported by the Office of Naval Research (ONR) through the CALYPSO Departmental Research Initiative (Grant N000141613130). Advanced field testing was supported by Woods Hole Oceanographic Institution internal funding. MATLAB routines for data processing are publicly available at https://github.com/mfreilich1/ecoctd_processing.2020-11-0

UCTD and EcoCTD Observations from the CALYPSO Pilot Experiment (2018): Cruise and Data Report

From May 27, 2018 to June 02, 2018, a scientific campaign was conducted in the Alboran Sea as part of an ONR Departmental Research Initiative, CALYPSO. The pilot cruise involved two ships: the R/V Socib, tasked with sampling fixed lines repeatedly, and the NRV Alliance that surveyed along the trajectory of Lagrangian platforms. A large variety of assets were deployed from the NRV Alliance, with the objective to identify coherent Lagrangian pathways from the surface ocean to interior. As part of the field campaign, an Underway-CTD (UCTD) system was used to measure vertical profiles of salinity, temperature and other properties while steaming, to achieve closely spaced measurements in the horizontal along the ship's track. Both a UCTD probe and an biooptically augmented probe, named EcoCTD, were deployed. The EcoCTD collects concurrent physical and bio-optical observations. This report focuses exclusively on the data collected by these two underway systems. It describes th e datasets collected during the pilot cruise, as well as the important processing steps developed for the EcoCTD.Funding was provided by the Office of Naval Research under Contract #N00014161313

Advanced modeling and simulation to design and manufacture high performance and reliable advanced microelectronics and microsystems.

An interdisciplinary team of scientists and engineers having broad expertise in materials processing and properties, materials characterization, and computational mechanics was assembled to develop science-based modeling/simulation technology to design and reproducibly manufacture high performance and reliable, complex microelectronics and microsystems. The team's efforts focused on defining and developing a science-based infrastructure to enable predictive compaction, sintering, stress, and thermomechanical modeling in ''real systems'', including: (1) developing techniques to and determining materials properties and constitutive behavior required for modeling; (2) developing new, improved/updated models and modeling capabilities, (3) ensuring that models are representative of the physical phenomena being simulated; and (4) assessing existing modeling capabilities to identify advances necessary to facilitate the practical application of Sandia's predictive modeling technology

Approaches to designing micro-solenoidal RF probes for 14 T MRI studies of millimeter-range sized objects

Full-wave electromagnetic simulations have been employed to analyze the design approaches that allow for solving the problems preventing inductive performance of micro-solenoidal RF probes and formation of strong and homogeneous magnetic fields inside probes at the studies of millimeter-range sized objects in 14 T MRI scanners. In particular, the effects of non-uniform coil wrapping on field homogeneity inside extended coils and of partitioning the coils by dielectric separators on coil self-resonances have been investigated. The possibility to utilize tunable C-C matching circuits with the coils and to mitigate the effects of sample insertion on the probe resonance frequency has been demonstrated. Challenges of coil fabrication have been also addressed

Development and experimental testing of microstrip patch antenna-inspired RF probes for 14 T MRI scanners

Radio frequency (RF) probes for ultrahigh-field magnetic resonance imaging (MRI) systems were developed from structures inspired by microstrip patch antennas. The patch structures provide an alternative to conventional surface coils. We show that these structures, operating as resonators, can produce strong magnetic fields, which act as B1 fields in MRI studies. The addition of high permittivity inserts to the patch substrate was beneficial for increasing B1 field uniformity. It was also shown by simulations that two vis-à-vis placed identical patches fed with 180° phase difference could produce uniform B1 field in the space between patches and could be used as volume RF probes. This possibility was confirmed by experiments with fabricated prototypes in the VARIAN 14.1 T MRI scanner. We further show that the B1 uniformity is enhanced over larger volume with properly profiled substrates of higher permittivity, along with smaller radiation losses. These probes were found competitive and even advantageous in comparison with birdcage coils because of better stability of their Q-factors at loading by lossy phantoms. Thus, patch-based probes offer a viable alternative to RF probes for ultrahigh field MRI

Modified design of the coil probe for high field MRI

© 2015 IEEE. Small RF coils for operating in Magnetic Resonance Imaging (MRI) 14T systems with Larmor frequency of 600 MHz for imaging seed assembles have been developed with the focus to improve the homogeneity of magnetic field inside the coils for obtaining higher image quality. The performed full-wave simulations have shown that uniformly wrapped coils fail to provide the desired field homogeneity, while non-uniform wrapping can be employed for achieving essentially more congruous field distributions

Unconventional designs of RF probes for high-field MRI to enhance magnetic field uniformity

© 2017 USNC-URSI. We present approaches to enhancing magnetic field uniformity produced by RF probes in high-field Magnetic Resonance Imaging (MRI) scanners by introducing compensating non-uniformities in the probe designs. Unconventional designs of RF probes for operating at 600 MHz in 14 T MRI scanners are demonstrated, including a solenoid coil with non-uniform wrapping and dielectric separators, a system of microstrip patch antennas with substrates engineered by using high permittivity inserts, and a system of specifically shaped patch antennas. The advantages of the proposed probe designs are discussed